It would be great if someone with an OpenBTS system
could turn on
debugging messages and capture the raw bits from our system
information messages 1-4 and send them to you for you to try in your
OpenBSC build.
Well, I already did that by using some traces I found in
http://wiki.thc.org/. There I copied some values for GPRS support and
changed that in OpenBSC source. Also added the missing SI 13 to the
source, which contains some more info about the GPRS, but without success.
I looked at the BCCH messages in OpenBSC yesterday,
but could not
identify the problem. I don't know how OpenBSC handles the "rest
octets" at the ends of these messages, but it is important that these
be properly padded with the GSM filler pattern if you are not coding
anything there. This is especially important for high-feature phones
that might actually be looking for GPRS parameters. It is also
important to present the BCCH messages in the correct sequence and
with the timing given in GSM 05.02 6.3.1.3, but I suspect your BTS
takes care of that for you.
In OpenBSC (I have older version, didn't do any updates yet) There are
SI 1 to 4 that are filled and the Rest Octets (in SI 3 and SI 4) are
filled with 0x2B, which the MS should ignore and thus it also indicates
no GPRS support.
I agree with your analysis. If the handset actually
sees the network,
then you do not have a frequency offset problem. Therefore, if you do
not see channel requests coming from the phone via the BTS the most
likely explanation is that the phone has found some inconsistency in
the BCCH.
Exactly, that's my assumption too. But as my collegue once said
"Assumption is the mother of all f@ck" from a movie scene of Steven
Seagal's film Under Siege 2. The fact is, it should/must work with BTSs
without GPRS, so I think some important basic information on the BCCH is
not complete and thus maybe corrupt in a certain way. Cause the same
problem also occurs with the BS11 BTS according to other guys in the
list. So I'll concentrate more on the BCCH and try to understand it
carefully.
Sorry. It's joking response: If I see you coming,
I will hide. Just
a joke, though.
No need for appolagize, I like jokes too :p It's funny we laugh about
jokes. Actually, we should always laugh and laugh harder when we hear a
joke. The world would be so beautiful than.
Greetings,
Laughing Nordin.